Suppression of fecundity of the root-knot nematode, Meloidogyne javanica, in monoxenic cultures of Arabidopsis thaliana treated with an alkaline extract of Ascophyllum nodosum

Abstract

Treatment of Arabidopsis thaliana plants with a commercially-available, alkaline extract of the marine brown alga, Ascophyllum nodosum, resulted in a significant decrease in the number of females of the root-knot nematode, Meloidogyne javanica, which developed in the roots compared to those of plants grown in a water control medium. Significant reductions in egg recovery were also achieved from plants treated with the seaweed extract. Similar effects were produced when betaine components of the seaweed extract (γ-aminobutyric acid betaine, δ-aminovaleric acid betaine and glycinebetaine) were used in quantities equivalent to those applied in the seaweed extract treatment. As the experiments were conducted under monoxenic conditions, it can be concluded that the results obtained with the application of either the seaweed extract or betaines are indicative of their effects on the plants and are not dependent on microorganisms associated with the rhizosphere.